Pierce nut installation head

ABSTRACT

The disclosure relates to an installation head apparatus, particularly suitable for securing a piercing fastener in a panel. The disclosed installation head includes a reciprocating plunger and a guide housing having a passage which receives the plunger and a plurality of pierce nuts in vertically stacked relation. The preferred embodiment of the guide housing provides an interference fit at the pierce nut corners to retain the nuts in the guide passage and explosion channels at the open end of the pierce nut passage which, in the event a pierce nut is fractured during the installation, receives the pierce nut fragments, guides the fragments away from the passage and prevents damage to the pierce nuts remaining in the passage.

United States Patent 1 Steward PIERCE NUT INSTALLATION HEAD [75]Inventor: Jerry H. Steward, Bloomfield Hills,

Mich.

[73] Assignee: Multifastener Corporation, Detroit,

Mich.

[22] Filed: June 3, 1971 [211 App]. No.: 149,516

[52] US. Cl. ..29/21l D, 29/200 P [51] Int. Cl ..B23q 7/10, B23p 19/00[58] Field of Search .-....29/2ll D, 200 P, 200 B, 432,

[56] References Cited UNITED STATES PATENTS 3,098,576 7/1963 Steward..22l/l3 X 1 March 6, 1973 Primary Examiner-Thomas H. EagerAttorney-Cullen Settle Sloman & Cantor 7 1 ABSTRACT The disclosurerelates to an installation head apparatus, particularly suitable forsecuring a piercing fastener in a panel. The disclosed installation headincludes a reciprocating plunger and a guide housing having a passagewhich receives the plunger and a plurality of pierce nuts in verticallystacked relation. The

preferred embodiment of the guide housing provides an interference fitat the pierce nut corners to retain the nuts in the guide passage andexplosion channels at the open end of the pierce nut passage which, inthe event a pierce nut is fractured during the installation, receivesthe pierce nut fragments, guides the frag ments away from the passageand prevents damage to the pierce nuts remaining in the passage.

9 Claims, 9 Drawing Figures PATENTED R 9 5 3,718,965 SHEET 10F 3 INVENTOR.

JERRY H. STE WARD.

CULLEN, SETTLE, SLOMAN a CANTOR.

ATT'YS.

Pm'mm 6W5 3,718,965

SHEET 20F 3 INVENTOR.

JERRY H. STE WARD. BY

CULLEN, SETTLE, SLOMAN a CANTIOR.

ATT'YS.

PATEIJTEU 61 75 SHEET 3 OF 3 INVENTOR.

JERRY H. STEWARD.

CULLEN, SETTLE, SLOMAN 8 CANTOR.

ATT' YS.

FIELD OF THE INVENTION The installation head of the invention isparticularly suitable for securing pierce nuts in a panel or the like. Apierce nut has a pilot portion which pierces its own hole in a panel anda flange portion which overlies the panel adjacent the pierced hole.During installation of the pierce nut, the panel may be deformed intosuitable grooves provided in the nut, such as disclosed in U. S. Pat.No. 3,187,796, which is assignedto the assignee of the instantapplication, or the deformed to retain the panel.

The preferred embodiment of the pierce nut installation head receives aplurality of nuts in vertical stacked relation for sequentialinstallation in a panel adjacent the head. The installation headincludes an actuatable plunger, a guide member or housing having an openended passage which receives the plunger and releasably retains the nutsin the vertical stacked relation. The plunger is actuatable to forciblyengage the uppermost nut in the nut stack and force the lowermost nutout of the open end of the passage to pierce the panel and retain thepierce nut in the panel. In the disclosed embodiment of the pierce nuthead, the guide housing passage engages the corners of the nuts toprovide an interference fit, thereby retaining the nuts in the passagefor engagement by the plunger. The disclosed embodiment of the piercenuts are generally rectangular and the guide housing passage is alsogenerally rectangular with radiused corners providing a four pointinterference fit with the pierce nuts.

In certain pierce nut installation applications, it may be possible torecycle the installation head after a pierce nut has been installed inthe panel. The pierce nut head may be'installed in a press platen, forexample, wherein the pierce nut is installed in the panel during theforming of the panel. If the head is damaged or jammed, the press may bedamaged. Further, the press must be disassembled and the head repairedof replaced, resulting in expensive delays. The pierce nut head of thisinvention avoids damage due to recycling of the head by providingchannels at the open end of the guide housing passage which communicatewith the passage and are open remote fromthe passage. In the event thatthe installation head is recycled after installation of a first nut, thesecond nut is forced into the pierce nut may be pierced hole previouslyoccupied by the first pierce nut. The pilot portion is thus forcedthrough the panel, but the flange portion is sheared or fractured andmay cause damage to the head assembly. The channels thus serve at leastthree functions: (1) the channels receive the pierce nut fragments, (2)the channels guide the fragments away from the guide housing passage,and (3) the channels prevent damage to the pierce nuts remaining in thepassage. In the disclosed embodiment, the bottom wall of the channelsare inclined away from the plane of the panel, thereby conducting thepierce nut fragments away from the panel.

Other improvements and meritorious features of the invention will morefully appear from the following description of the preferred embodiment,[claims and drawings.

2 BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation,partially cross sectioned of one embodiment of the pierce nutinstallation head of this invention;

FIG. 2 is a top cross sectional view of the pierce nut installation headshown in FIG. I, in the direction of view arrows 2--2;

FIG. 3 is an enlarged sectional view of a portion of the pierce nut headshown in FIGS. 1 and 2;

FIG. 4 is a top view of the guide housing shown in FIG. 1;

FIG. 5 is a side cross sectional view of the guide housing shown in FIG.4, in the direction of view arrows 5-5;

FIG. 6 is a bottom view of the guide housing shown in FIG. 4;

FIG. 7 is a bottom perspective view of the guide housing shown in FIGS.4 to 6; and

FIGS. 8 and 9 are partially cross sectioned views of the lower housingassembly shown in FIG. 2, in the direction of view arrows 8-8, showingthe function of the relief channels.

DESCRIPTION OF THE PREFERRED EMBODIMENT The head assembly 20 shown inFIG. 1 is adapted to receive a plurality of pierce nuts 22 forsequential securement in a panel or the like. The pierce nutinstallation head shown in FIG. 1 has three main parts, including theupper housing assembly indicated generally at 24, the lower housingindicated generally at 26 and the guide post assembly indicatedgenerally at 28. Many of the details of the disclosed head assembly maybe the same as the head assembly shown in U.S. Pat. Nos. 3,089,670 and3,098,576, which are assigned to the assignee of the instantapplication. Reference may be had to these patents for details of theupper housing assembly 24 and the guide post assembly 28, for example,which are not disclosed herein. The above reference patents alsodisclose in more detail the method of installing a pierce nut in apanel, including the method of feeding the pierce nuts to theinstallation head. In the method disclosed in the above patents, thepierce nuts are fed to the pierce nut installation head 20 through metalor plastic chuting from a rotating hopper or the like. Any suitable feedsystem may how ever be utilized in the pierce nut installation headassembly of the invention.

In the disclosed embodiment, the pierce nut installation head 20 issecured in a platen 30 of a punch press or the like by a cap screw 32which secures the upper housing assembly 24 to the press platen. A plate34 is provided between the upper housing assembly and the press platento prevent brinelling of plunger 48 into platen 30. In this embodiment,an aperture 36 is provided in the plate which is configured to receivethe guide post assembly 28 as described hereinbelow. The guide postassembly is secured to the upper housing by a retaining pin 38 which isreceived in a key slot in the guide post assembly, not shown. The guidehousing or nose piece 40, which forms part of the lower housingassembly, includes an extension 42 which is received in and secured to aflat recess 44 in the guide post assembly 28.

When the press platen 30 is actuated toward the panel, not shown, theguide housing 40 engages the panel, forcing the guide housing 40 andguide post assembly 28 toward the press platen and the plunger 48 towardthe panel. The guide post assembly 28 is received in the configuredaperture 36, permitting relative movement between the guide housing 40and the upper housing assembly and plunger 48.

The pierce nuts are fed to the guide housing 40 through feed chute 46.The plunger 48 in this embodiment is provided with a reduced portion 50adapted to engage the pierce nuts 22. The configuration of the reducedportion will depend upon the size and shape of the pierce nuts. Theplunger 48 is secured within an opening 52 in the upper housing assembly24. The reduced portion 50 of the plunger is received in a machinedpassage 54 in the housing guide of nose pierce 40 as describedhereinbelow.

The details of the guide housing 40 are shown in FIGS. 4 to 7, whereinthe passage 54 is generally rectangular as shown in FIGS. 4 and 6 toreceive a generally rectangular pierce nut. It will be understood thatthe configuration of the passage will depend upon the shape of thefastener received therethrough. In this embodiment, a plurality ofpierce nuts 22 are received in vertically stacked relation, as shown inFIG. 5, for engagement by the plunger 50. The pierce nuts are receivedthrough opening 55 to the vertical passage 54. In this embodiment, thefasteners 22 are retained in the vertical passage 54 at the corners ofthe fastener as shown in FIG. 3. The generally rectangular passage 54 isprovided with radiused corners 56 which provide an interference fit withthe pierce nuts 22 and releasably retain the fasteners in the passageuntil engagement by the plunger. The bottom wall 57 of the guide housingin this embodiment is provided with a pair of configured recesses 58which prevent the pulling out of a pierce nut after it is installed inthe panel. The recesses receive the flanged portion of the pierce nut,after it is received in the panel, providing clearance between theflanged end of the pierce nut and the passage 54, which is restricted bythe radiused corners 56 as shown in FIG. 3. The opposed channels 60provide an explosion relief in the event the pierce nut installationhead is recycled as described above and as shown in FIGS. 8 and 9. Inthe event that the installation head is recycled after installation of anut, as shown in FIG. 8, the second nut is forced into the pierced holepreviously occupied by the first pierce nut as shown in FIG. 9.

In this embodiment, the explosion channels include an inclined bottomwall 62 which is inclined away from the plane of the panel 63, as shownin FIGS. 8 and 9, and a pair of generally vertical side walls 64. Thechannel opens into the passage 54 at 66 as shown in FIG. 7. It will beunderstood that the configuration of the channels will depend upon theparticular application of the pierce nut head. For example, in certainapplications the bottom wall 62 of the channel may be generally parallelto the plane of the panel or even inclined toward the panel, as requiredby the application.

The pierce nuts 22 in this embodiment of the pierce nut installationhead are generally rectangular, as described above, and include agenerally rectangular body portion 68, a pilot or piercing face 70 and apair of opposed flanges 72 opposite the piercing face. The nuts arereceived in the passage 54 in vertically stacked relation, as shown inFIGS. 8 and 9, with the pilot face disposed toward the panel 63. Whenthe plunger 50 is actuated toward the panel 63, as described above, oneof the pierce nuts is forced out of the open end of the passage 54 topierce the panel 63 as shown in FIG. 8

If the pierce nut installation head is recycled, wherein another piercenut is received in the channel 54 and the plunger forces another piercenut in the panel, the body portion 68 of the first pierce nut is forcedthrough the panel aperture, as shown in FIG. 9, and the second piercenut is installed in the panel in the place of the first pierce nut. Theflanges 72, however, which normally overlie the panel, are sheared offin the second installation step, usually with considerable force. Thechannels 60 receive the fractured flanges and conduct the fragments awayfrom the passage, preventing damage to the pierce nut installation headand the pierce nuts remaining in the passage 54. If the channels werenot provided, the pierce nuts would jam in the head, rendering thepierce nut head useless.

It will be understood that various details of the pilot housing 40 andthe pierce nut installation head 20 are dependent upon the particularshape and configuration of the pierce nut to be installed and thereforevarious modifications may be made to the disclosed pierce nutinstallation head of this invention without departing from the purviewof the claims which follow. For example, the passage 54 could beconfigured to receive an octagonal pierce nut.

I claim:

1. A pierce nut installation head adapted to receive a plurality ofpolygonal pierce nuts for sequential installation in a panel adjacentthe head, comprising: an actuatable plunger, a guide member having anopen ended passage receiving said plunger for reciprocal movementtherein, a plurality of polygonal pierce nuts in said passage in stackedrelation opposite an end of the plunger, said passage generallyperipherally confining said nuts in said stacked relation therein andbeing somewhat larger than the nuts to permit movement of the nutstherethrough upon engagement by the plunger, portions of said passageengaging at least two corners of the polygonal pierce nuts to provide aninterference fit, thereby releasably retaining the nuts in the passage,said plunger actuatable to forcibly engage the uppermost nut in the nutstack and force the lowermost nut out of said open end of the passageagainst the panel to secure the pierce nut in the panel.

2. The pierce nut installation head defined in claim 1, characterized inthat said pierce nuts are generally rectangular and said passage isgenerally rectangular with radiused corners providing a four pointinterference fit with said pierce nuts at the corners of said piercenuts.

3. The pierce nut installation head defined in claim 1, characterized inthat said guide member includes a plurality of channels adjacent saidopen end of the passage communicating with said passage and adapted toreceive and guide fragments of the pierce nuts away from the passage inthe event that a nut is fragmented during installation.

4. The pierce nut installation head defined in claim 3, characterized inthat said channel includes a bottom wall inclined away from the open endof said passage to guide nut fragments away from the panel.

5. A pierce nut installation head adapted to receive a plurality ofpierce nuts and sequentially secure said nuts in a panel, said piercenuts each having a pilot portion for piercing a hole in a panel and aflange portion for overlying the panel adjacent the pierced hole, saidpierce nut installation head comprising a plunger, a

guide member adapted to be positioned adjacent the panel having an openended passage receiving said plunger for reciprocal movement thereintoward the panel, said pierce nuts being received within said passagebetween said plunger and the panel in vertical stacked relation, eachpierce nut having its pilot portion facing the panel, said plungeractuatable within said passage to force one pierce nut out of the openend of said passage toward the panel, causing the pilot portion of saidone pierce nut to pierce the panel, and said guide member having achannel adjacent said open end of the passage, communicating with saidpassage and having an open end remote from said passage, said channelfunctioning, in the event said flange portion is fractured to 1) receivefragments of the flange portion of said pierce nut, (2) guide thefragments away from flange portions.

7. The pierce nut installation head defined in claim 5, characterized inthat said channel have a bottom wall inclined away from the plane ofsaid panel to guide said fragments away from said panel.

8. The pierce nut installation head defined in claim 5, characterized inthat said pierce nuts are polygonal having a plurality of corners andsaid passage in the guide member engages at least two corners of thepierce nuts to provide an interference fit, thereby releasably retainingthe nuts in the passage.

9. The pierce nut installation head defined in claim 8, characterized inthat said pierce nuts are each generally rectangular and said passage isgenerally rectangular with radiused corners providing a four pointinterference fit with said pierce nuts at the corners of each of saidpierce nuts.

1. A pierce nut installation head adapted to receive a plurality ofpolygonal pierce nuts for sequential installation in a panel adjacentthe head, comprising: an actuatable plunger, a guide member having anopen ended passage receiving said plunger for reciprocal movementtherein, a plurality of polygonal pierce nuts in said passage in stackedrelation opposite an end of the plunger, said passage generallyperipherally confining said nuts in said stacked relation therein andbeing somewhat larger than the nuts to permit movement of the nutstherethrough upon engagement by the plunger, portions of said passageengaging at least two corners of the polygonal pierce nuts to provide aninterference fit, thereby releasably retaining the nuts in the passage,said plunger actuatable to forcibly engage the uppermost nut in the nutstack and force the lowermost nut out of said open end of the passageagainst the panel to secure the pierce nut in the panel.
 1. A pierce nutinstallation head adapted to receive a plurality of polygonal piercenuts for sequential installation in a panel adjacent the head,comprising: an actuatable plunger, a guide member having an open endedpassage receiving said plunger for reciprocal movement therein, aplurality of polygonal pierce nuts in said passage in stacked relationopposite an end of the plunger, said passage generally peripherallyconfining said nuts in said stacked relation therein and being somewhatlarger than the nuts to permit movement of the nuts therethrough uponengagement by the plunger, portions of said passage engaging at leasttwo corners of the polygonal pierce nuts to provide an interference fit,thereby releasably retaining the nuts in the passage, said plungeractuatable to forcibly engage the uppermost nut in the nut stack andforce the lowermost nut out of said open end of the passage against thepanel to secure the pierce nut in the panel.
 2. The pierce nutinstallation head defined in claim 1, characterized in that said piercenuts are generally rectangular and said passage is generally rectangularwith radiused corners providing a four point interference fit with saidpierce nuts at the corners of said pierce nuts.
 3. The pierce nutinstallation head defined in claim 1, characterized in that said guidemember includes a plurality of channels adjacent said open end of thepassage communicating with said passage and adapted to receive and guidefragments of the pierce nuts away from the passage in the event that anut is fragmented during installation.
 4. The pierce nut installationhead defined in claim 3, characterized in that said channel includes abottom wall inclined away from the open end of said passage to guide nutfragments away from the panel.
 5. A pierce nut installation head adaptedto receive a plurality of pierce nuts and sequentially secure said nutsin a panel, said pierce nuts each having a pilot portion for piercing ahole in a panel and a flange portion for overlying the panel adjacentthe pierced hole, said pierce nut installation head comprising aplunger, a guide member adapted to be positioned adjacent the panelhaving an open ended passage receiving said plunger for reciprocalmovement therein toward the panel, said pierce nuts being receivedwithin said passage between said plunger and the panel in verticalstacked relation, each pierce nut having its pilot portion facing thepanel, said plunger actuatable within said passage to force one piercenut out of the open end of said passage toward the panel, causing thepilot portion of said one pierce nut to pierce the panel, and said guidemember having a channel adjacent said open end of the passage,communicating with said passage and having an open end remote from saidpassage, said channel functioning, in the event said flange portion isfractured to (1) receive fragments of the flange portion of said piercenut, (2) guide the fragments away from said passage, and (3) preventdamage to the pierce nuts remaining in said passage.
 6. The pierce nutinstallation head defined in claim 5, characterized in that said piercenuts each include two opposed flange portions and said guide memberincludes two opposed channels extending away from opposed sides of saidpassage, generally aligned with said flange portions.
 7. The pierce nutinstallation head defined in claim 5, characterized in that said channelhave a bottom wall inclined Away from the plane of said panel to guidesaid fragments away from said panel.
 8. The pierce nut installation headdefined in claim 5, characterized in that said pierce nuts are polygonalhaving a plurality of corners and said passage in the guide memberengages at least two corners of the pierce nuts to provide aninterference fit, thereby releasably retaining the nuts in the passage.